In a typical application, a rolling bearing arrangement may be arranged to accommodate misalignment, shaft deflections and thermal expansion of the shaft. To cope with misalignment and shaft deflections, design engineers conventionally use a self-aligning bearing arrangement consisting of two self-aligning ball bearings or two spherical roller bearings. However, thermal expansion of the shaft is a complex issue and one of the bearings is often arranged as a “locating” bearing and the other as a “non-locating” bearing. For example, the locating bearing may be secured in the housing and on the shaft and the non-locating bearing may be arranged to be able to move axially on its seat in the housing. However, the movement in relation to the housing of the non-locating bearing moves typically generates a considerable amount of friction, which then induces vibration, axial forces in the bearing system, and heat—all of which can significantly reduce bearing service life.
For various applications, a known solution involves utilizing a toroidal rolling element bearing, which is a self-aligning radial bearing having an inner ring that moves independently of the outer ring, enabling e.g. thermal elongation and contraction of the shaft or structure due to temperature variations without inducing internal axial loads. Furthermore, since the inner and outer rings of a toroidal roller bearing can be mounted with an interference fit, problems associated with a loose outer ring, such as fretting corrosion and distortion of the ring may be avoided.
However, for applications involving thrust loads, design engineers are required to coop with high axial loads, misalignment and shaft deflections. Known solutions and design rules suffer from resulting bearing arrangements having low design freedom, are expensive and over dimensioned.